Cold atmospheric plasma–antioxidant synergy improves the gel structure of squid surimi

Cold atmospheric plasma (CAP) inactivates proteases in squid surimi but induces protein oxidation. This study evaluated three antioxidants—tea polyphenols (TP), butylated hydroxyanisole (BHA), and octyl gallate (OG)—for mitigating CAP-induced oxidation. CAP treatment significantly enhanced the radical-scavenging capacity of the antioxidants, particularly TP (38.63% increase in ABTS) and OG (8.41% increase in DPPH), likely by activating phenolic hydroxyl groups. While CAP alone improved whiteness and gel strength, it reduced sulfhydryl content and Ca2+-ATPase activity, indicating protein oxidation. However, combining CAP with TP or OG effectively preserved protein integrity, promoted the formation of disulfide bonds and hydrophobic interactions, and enhanced storage modulus, water-holding capacity, and texture. These findings demonstrate that natural polyphenols constructively moderate CAP-induced oxidation, offering a promising strategy for improving surimi quality and functionality in aquatic food processing.